diff --git a/src/main/java/de/uniluebeck/mi/projmi6/hapi/HL7Sender.java b/src/main/java/de/uniluebeck/mi/projmi6/hapi/HL7Sender.java
index e9ff94e..cbebf12 100644
--- a/src/main/java/de/uniluebeck/mi/projmi6/hapi/HL7Sender.java
+++ b/src/main/java/de/uniluebeck/mi/projmi6/hapi/HL7Sender.java
@@ -8,6 +8,7 @@ import ca.uhn.hl7v2.app.HL7Service;
 import ca.uhn.hl7v2.app.Initiator;
 import ca.uhn.hl7v2.llp.LLPException;
 import ca.uhn.hl7v2.model.Message;
+import ca.uhn.hl7v2.model.v251.message.ACK;
 import ca.uhn.hl7v2.model.v251.message.ADT_A01;
 import ca.uhn.hl7v2.model.v251.segment.*;
 import ca.uhn.hl7v2.parser.Parser;
@@ -128,25 +129,22 @@ public class HL7Sender {
             Initiator initiator = connection.getInitiator ();
             Message response = null;
             try {
-                response = initiator.sendAndReceive ( adt );
+                while (! (response instanceof ACK)) {
+                    response = initiator.sendAndReceive ( adt );
+                    Thread.sleep ( 5000 );
+                }
             } catch (HL7Exception e) {
                 e.printStackTrace ();
             } catch (LLPException e) {
                 e.printStackTrace ();
             } catch (IOException e) {
                 e.printStackTrace ();
-            }
-    /*
-            String responseString = null;
-            try {
-                responseString = p.encode ( response );
-            } catch (HL7Exception e) {
+            } catch (InterruptedException e) {
                 e.printStackTrace ();
             }
-            System.out.println ( "Received response:\n" + responseString );
-            */
 
-               /*
+/*
+
         * Close the connection when you are done with it.
         */
             connection.close ();